fe-safe

Durability Analysis Software for Finite Element Models

Verity® Module in fe-safe

For welded joints and welded structures, including spot welds, the prediction of failure locations and the calculation of fatigue lives have traditionally been notoriously complex and difficult tasks that can often result in poor correlation with test data. The Verity mesh-insensitive Structural Stress Method has been developed and patented by Battelle. It is recognized as a major breakthrough in the fatigue analysis of welded joints for finite element models.

Verity in fe-safe combines Verity for the fatigue of welded structures with the advanced features of fe-safe for fatigue analysis for finite element models. It allows companies to reduce or avoid the expense of testing to validate the integrity of designs and avoid the common practice of over-engineering due to the uncertainty of fatigue life.

Redesign of a Critical Component for Higher Fatigue Life
"Verity Module in fe-safe allows our clients to efficiently manage the reliability of their cyclic equipment, which ultimately leads to improved safety and considerable economic advantages"
The Equity Engineering Group, Inc.
At a Glance

Verity in fe-safe

  • Removes the subjective decisions by the user, thereby increasing reliability and accuracy
  • Works from nodal forces at the weld toe - not some subjective distance from the weld toe
  • Uses a single master S-N curve and can be used for all welds and for all thicknesses of sheet and plate
  • Offers consistent structural stress calculations regardless of mesh size or element types
  • Achieves new levels of accuracy and reliability
  • Is mesh-insensitive
  • Can be applied to all types of welds, including spot welds, and all types of loading
  • Can also be applied to other sharp notches such as thread roots
  • Is easy to use and automate
  • Analyses welded joints, spot welds and non-welded areas in a single run
  • Has been validated by Battelle's Joint Industry Project using more than 3500 physical fatigue tests

Verity Module in fe-safe is an add-on module to fe-safe, enabling users to include the effects of complex loading histories, multiaxial fatigue, and other advanced capabilities in fe-safe.

Capabilities
  • Verity Module in fe-safe is based on nodal forces at the weld toe - not some subjective distance from the weld toe
  • Nodal forces are much less sensitive to mesh density than standard FEA stresses. An analysis based on nodal forces, and therefore Verity, is mesh-insensitive
  • A single master S-N curve can be used for all welds, be they structural welds, seam welds, spot welds or solder joints... for all thicknesses of sheet and plate and for all types of loading
  • There are no subjective decisions needed to be made by the user
  • Offers consistent structural stress calculations regardless of mesh size, element types, or the finite element software used - a critical step to realizing 6 sigma in CAE applications
  • Can be used with coarse meshes of solid or shell elements
  • Allows the option of further improving the accuracy of fatigue life predictions by allowing the user to formulate their own custom master S-N curve based on proprietary data
  • Is supported by third party tools from Altair, ANSYS and BETA CAE Systems for simplifying the definition of weld domains
  • The "Auto-Detect" tool for spot welds automatically detects the number of sheets welded together, the thickness of each sheet, and the location of each spot weld. Very short analysis times are obtained even with models that contain many thousands of spot welds
  • Verity is cited as an approved method in:
    • ASME Section VIII, Division 2, Part 5 Design By Analysis
    • API 579-1/ASME FFS-1 Fitness-For-Service
Benefits

As the original, patented Structural Stress Method, Verity is the most well validated of all the Structural Stress approaches.

 

Key Benefits include:

  • Removal of subjective decisions by the user, thereby increasing reliability and accuracy
  • Welded joints and non-welded areas can be analyzed in a single run and the results displayed on the same contour plot, thereby speeding up whole model analyses
  • Significant reductions in CAE and FEA modeling time
  • Lower development costs as a result of minimizing the need for physical validation testing
  • Inspecting and testing components against fatigue criteria can lower "classification" or regulatory compliance costs
  • Optimized designs and lighter structures as a result of less reliance on over-designing to account for uncertainty
  • Direct interfaces to leading FEA suites such as Abaqus, ANSYS, I-deas, and Nastran (MSC, NEi, NX) are driven from an intuitive, single screen, Windows-based GUI
  • The "Auto-Detect" tool for spot welds enables fast analysis times for models containing many thousands of spot welds

 

Verity has been validated for applications ranging from the automotive to offshore/marine industries, through collaboration with leading engineering companies who are members of Battelle's Joint Industry Project (JIP). The effectiveness of the method has been demonstrated by collapsing into a single curve many thousands of fatigue tests from lab specimens and full scale components, obtained and verified from open literature. This is the ‘master S-N curve'.

Verity has received many prestigious awards including: TIME Magazine's Math Innovators (2005), Aviation Week and Space Technology's 2004 Laurels Award; and SAE's Henry Ford II Distinguished Award for Excellence in Automotive Engineering (2003). Business Week dubbed Verity as "A Bolt of Genius in Welding" (2004).